The proposed project involves the identification and isolation of the protein components of the following membrane transport systems of Escherichia coli: Ribose, glutamate-aspartate (two systms), glutamate-methylglutamate, dicarboxylic acid, branched chain amino acid (at least three systems), and proline. For these systems where we have already isolated the substrate recognition protein components (ribose, glutamate-asparatate, and branched chain amino acids) we will attempt to generate frameshift mutants devoid of the additional proteins required for transport with the aim of identifying and isolating the auxiliary protein components. For the remaining systems we will utilize the transport-negative mutants (frameshifted) that we have already generated in attempts to identify and isolate the membrane bound protein component(s) involved in the active transport of these nutrients across the cytoplasmic membrane.